Donald Trump’s allies and some in the private sector have been quietly preparing to detain and deport migrants residing in the United States on a large scale, according to four sources familiar with the discussions, CNN reports.

And with the former president becoming the president-elect, those preparations are now expected to ramp up.

Trump’s day one priority is to reinstate his former administration’s border policies and reverse those of President Joe Biden, senior Trump adviser Jason Miller told CNN.

Early discussions among Trump’s team have focused on removing undocumented immigrants who have committed crimes, a source familiar with the team’s preliminary plans told CNN. A key issue under consideration is how, when and if to deport immigrants who were brought to the United States as children, commonly known as Dreamers.

Targeting Dreamers would be a departure from the historically bipartisan support they’ve enjoyed. Some are temporarily protected by the Obama-era Deferred Action for Childhood Arrivals program that allows recipients to live and work in the US.